You are not supposed to "identify" anything on UNIX-like operating systems; that is what the file(1) command is for, specifically, especially so since the entire concept of UNIX is that everything is a stream of bytes.
Attempting to manually manage files in this way defeats the purpose of the OS abstracting it away for the user; and the users of your executable should not have to care what your executable is written in because you grew up on a PC-bucket whose operating system stems from CP/M -> MS-DOS!
As someone who did grow up on Windows and still uses it regularly alongside Linux, I want to respond to this comment just to play the Devil's advocate (i.e. infuriate you).
> especially so since the entire concept of UNIX is that everything is a stream of bytes.
I consider this an archaic, anachronistic, ancient, outdated, primitive (they all mean the same thing; I just used a thesaurus to really drive home my point) file model. While it made sense for the limited computers of the early 1970s, it is extremely hobbling today and the fact that no one really complains about it is... quite astounding. If every file is merely a bag of bytes, then every native program shall have its own file-parsing/byte-parsing routine. What a waste of effort, writing and rewriting parsers over and over again.
The fact that one has to write a shell script that is interpreted, and itself calls not one, but three other binaries (cat, grep, awk) with arcane, not-easily-remembered flags just to extract out certain words in the last several lines of a file is... ridiculous. That you have to call 'file' instead of directly querying the OS or shell for file attributes is farcical. Consider PowerShell or Python as alternatives to shell scripting. In the former, the entire .NET library is available; in the latter, the default libraries may be imported as one sees fit, and additional libraries are available online.
> defeats the purpose of the OS abstracting it away for the user
The UNIX philosophy does a poor job of 'abstracting it away from the user'. For well-abstracted OSes, see any smartphone today (especially iPhones).
Furthermore, not every UNIX/Linux user interacts with their computer solely over the command line; I use KDE Plasma, for instance. In general, when I see a file on Linux with no extension, I expect it to be a binary; I am surprised when it is, in fact, a shell script.
This is a fantastic response, honestly. I'll add that your last point about how different users interact with their systems differently is especially relevant for the longevity of open operating systems. General users coming over to Linux who do not have extensive knowledge with computers beyond Windows will primarily be using graphical interfaces on their desktop, and making that process confusing for them by not accommodating that will quickly make them give up on the whole thing. If we wish to keep the software alive with a userbas then it's actually extremely important to allow and support things like this that are more intuitive.
Attempting to manually manage files in this way defeats the purpose of the OS abstracting it away for the user; and the users of your executable should not have to care what your executable is written in because you grew up on a PC-bucket whose operating system stems from CP/M -> MS-DOS!